In many instances, it is useful to provide an oven that cooks or heats food products by using steam. Specific uses of such steam ovens may vary, but one particular use is on board aircraft or other transportation vehicles in order to provide a quick, safe, and convenient method for cooking, heating, or re-heating food products.
Some existing steam ovens generate steam by injecting water directly or indirectly onto heating elements of the oven. In some systems, the water is injected inside a warm oven in a mist form, and when the water mist contacts the heating elements or the fan, the mist vaporizes instantly and becomes steam. Other steam ovens generate steam by dripping water into a recessed or depressed tray at the base (or bottom inside surface) of the oven. Other steam ovens deliver steam via water reservoir systems, such as those described in pending U.S. Ser. No. 12/688,483 titled “Oven Steam Generator Systems and Methods.”
The water for steam ovens located on-board passenger transport vehicles is typically delivered to the steam oven via the vehicle's water lines. For example, in the aircraft context, water from the on-board pressurized water system is delivered to one or more steam ovens via the aircraft's water lines. These are typically the same water lines that are used to deliver potable water to the coffee makers and any other on-board equipment that requires fresh water use.
When an aircraft is at the gate or otherwise unpowered, its water lines are depressurized and water is allowed to drain back into the on-board water tank or out of the aircraft entirely. Draining the water lines helps prevent water in the lines from freezing during cold temperatures, which can rupture or otherwise damage the lines or associated systems. It also prevents bacteria from building up in trapped, stagnant water if allowed to sit in the steam oven or in the water lines. However, even when the water lines are drained, only the water in the lines behind the vacuum break is allowed to drain, which can leave several feet of line in the steam oven water lines that is not appropriately drained. The result is that even though the aircraft water lines are periodically depressurized and drained, the water in the steam oven system is not drained effectively.
Current steam ovens for use on-board aircraft and other transportation vehicles do not provide appropriate draining features. They either fail to include a drain option entirely, or they require power to be available in order to operate a solenoid valve in the oven for draining the steam generator and associated plumbing system. Accordingly, a solution is needed to efficiently and automatically drain water out of steam ovens that are located on-board aircraft and other passenger transport vehicles.